1. Field of the Invention
The present invention relates to an imaging apparatus, such as a digital camera including an optical zoom function and an electronic zoom function.
2. Description of the Related Art
Conventionally, for the purpose of quickly capturing an image of an object and performing image processing, a camera system capable of performing quick and accurate adjustment of an angle of view by an operation of a zoom lever is required. Japanese Patent Application Laid-Open No. 2004-252370 discusses an improvement in operability of such a zoom lever operation by using a camera system that eliminates the need for fine adjustment of the angle of view which has been adjusted by the zoom lever or a zoom ring. According to the camera system, a user designates a region to be enlarged by a frame if the user desires to zoom-in. On the other hand, if the user desires to zoom back, the user determines the reduction ratio after confirming the reduced image. Then, the zooming is automatically performed according to a predetermined operation.
The zooming speed of the camera system discussed in Japanese Patent Application Laid-Open No. 2004-252370 can be set by the user to a desirable speed in advance of the operation. However, the setting method of the speed is not discussed in Japanese Patent Application Laid-Open No. 2004-252370.
Generally, the angle of view is difficult to adjust if a high power zoom lens is used since the camera shake has a significant effect on the imaging. Thus, the object may be frequently lost even if the angle of view is set. In such a situation, it is difficult to quickly change the angle of view to the wide-angle by the zoom lever and then change the angle of view back again after capturing the object.
On the other hand, if a framing button is provided in addition to the zoom lever, the user can easily perform the framing during the high zoom magnification imaging by pressing the framing button. When the framing button is pressed, the current zoom position is stored and the zoom is driven to a wide-angle position which is acquired based on the current zoom ratio. When, the user releases the framing button, the position is changed back to the stored zoom position. In the following description, this function is referred to as the “framing assist” function.
Unlike the operation by the zoom lever, the target zoom position of the framing assist function is determined before the drive. Thus, a miss operation such as overshooting does not occur even if the zooming is performed at a high speed. Accordingly, the zooming can be controlled at high speed. However, if the camera is in a moving image mode, unlike the angle of view adjustment of the imaging of a still image, the continuity of the recorded video image becomes important.
There are two types of operations concerning the zoom framing assist function. One function is used for driving the zoom in the wide-angle direction to capture the object in the angle of view. The other function is used for zooming in on the captured object. Since driving the zoom in the wide-angle direction (the former function) is used for capturing the object, high speed zooming in the wide-angle direction is required. In contrast, for zooming in on the captured object, a smooth operation is given priority in changing the angle of view rather than the speed of the operation with respect to the latter function so that the captured object is not lost.